It's a big problem, as soon as you have non-clinical FTE it's easy to take advantage of you. I am 0.1 non clinical, but the expectation is I be available for all sorts of meetings, committees, etc - and that an hour meeting only counts as an hour. So in admin's mind, they get me almost 100 days a year on call for 1 hour meetings, which is clearly insane.
I found boundary setting to work kind of - I say "this week I'm on nights, so I'm not available at all". "This week I'm on vacation" (even if I'm not actually going out of town, its a staycation from work). That being said I still end up giving them 40-50 days that I'm doing something at the hospital, at which point I really do lose my hospitalist lifestyle but I really enjoy my job so at least for now I go with it.
Some of my group members are much better. For one guy, he's made it very clear that he is not available except when he wants to be, and will not show up if it doesn't work for his schedule. He essentially doesn't answer emails unless he's on service, and it's rare for admin to call with a meeting request. He sets an out of office auto reply that says "I'll be back whatever day and checking all emails then, call if you need something urgent" but doesn't give a phone number